Cells damaged by hyperglycemia are unable to downregulate glucose entrance in presence of high extracellular glucose resulting in intracellular activation of deleterious biochemical pathways. Expression of GLUT-1, the major glucose transporter in mesangial cells, is increased and participates in the induction of diabetic nephropathy. Variants in the gene encoding GLUT-1 (SLC2A1) have been associated to this diabetic complication. The aim of this study was to test whether polymorphisms in SLC2A1 confer susceptibility to diabetic nephropathy in Brazilian type 1 diabetes patients.